Troubleshooting Moisture
© Hirschmann Rev. I 05/22/17
190154_I.DOC
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4) Defective Gasket
The gasket underneath the lid seals the unit. The gasket needs to be in good condition in order to
seal correctly. If the gasket is torn, brittle or severely bent, it needs to be replaced. Order a new
gasket through your PAT representative.
5) Loose Strain Relieves
The strain relieves allow cabling to enter the box without allowing water to enter it. The strain
relieves have to be correctly tightened in order to do this. Check the tightness by taking the
external cable into one hand and carefully trying to turn it. If the internal wires turn with the outer
cable, the strain relief is loose. Get a new grommet (insert) through your PAT representative and
replace the existing one with the new one. Tighten the strain relief correctly. Note: Whenever a
strain relief is opened, i.e. to replace a cable, a new grommet needs to be used. Never re-use any
grommet or the strain relief will not seal properly!
6) Water Entry Through External Cabling
Even with a tight strain relief, water may still enter the box through the inside of the cable. In this
case, you have to find out why and where water enters the cable. Look for damages to the cable
itself and inspect the opposite side of the cable. In example, if the cable comes from a connector
that is full of water, the water will run through the inside of the cable and fill up the central unit, too.
19.2 CONDENSATION
In a climate with high humidity and rapidly changing temperatures, condensation can happen inside
any enclosure, usually the larger the volume of the box, the more likely. In this case, water drops build
up on the inner components when humid air is trapped inside the box. With condensation, water
tightness is not a problem
– the box is sealed just fine, which is what prevents the trapped air from
exiting the box. There are two ways to deal with condensation:
1.
If the volume is very small, a desiccant bag might be able to soak up the air’s humidity.
2. If the effect is more severe, the only way to get rid of this effect is then to give the box the
ability to breath without sacrificing its water tightness. Contact your PAT representative for
breathing elements to than can be added to the box and will help to reduce the effects of
humid climates.
